Rolling bearing arrangement

Abstract

A rolling bearing arrangement for a turbocharger is comprised of a bearing housing relative to which a rolling bearing is supported. The rolling bearing is securely provided with an outer sleeve which is disposed to surround the periphery of the rolling bearing. The rolling bearing is supported through the outer sleeve on the bearing housing. A first annular space is defined between the outer sleeve and the inner periphery of the bearing housing. An oil inlet opening is opened at the inner periphery of the bearing housing so that lubricating oil is supplied through the oil inlet opening to the first annular space. An oil film damper clearance is formed between the outer sleeve and the bearing housing inner periphery and located adjacent the first annular space in the axial direction of the outer sleeve so that the entire flow of lubricating oil supplied to the first annular space passes through the oil film damper clearance. A second annular space is defined between the outer sleeve and the bearing housing inner periphery so that at least a part of the lubricating oil passed through the oil film damper clearance is supplied to the second annular space. An oil supply passage is so formed that lubricating oil from the second annular space is introduced to the rolling bearing. Additionally, an oil bypass passage is so formed that lubricating oil from the second annular space is introduced to an oil outlet opening through which the lubricating oil is discharged out of the bearing housing.

What is claimed is: 
     
       1. A rolling bearing arrangement comprising: a bearing housing;   a pair of rolling bearings, supported to provide support to a shaft therebetween relative to and adjacent opposite ends of said bearing housing;   a pair of outer sleeves with one outer sleeve secured to and surrounding the periphery of each of said rolling bearings, sid rolling bearings being respectively supported through said outer sleeves to said bearing housing;   a pair of first annular spaces, respectively defined between an outer peripheral surface of each of said outer sleeves and an inner peripheral surface of said bearing housing;   an oil inlet opening opened at an inner periphery of said bearing housing, a flow of lubricating oil being supplied through said oil inlet opening to said first annular spaces;   an oil film damper clearance formed between each of said outer sleeves and said bearing housing inner periphery and located adjacent each of said first annular spaces in an axial direction of said outer sleeve, the entire amount of a lubricating oil flow supplied to said first annular spaces passing through said oil film damper clearance;   a second pair of annular spaces, respectively defined between said outer sleeves and said bearing housing inner periphery, at least a part of the lubricating oil flow passed through said oil film damper clearance being supplied to said second annular spaces;   an oil supply passage formed in each of said outer sleeves adjacent to and inboard of the corresponding rolling bearing supported therein, whereby lubricating oil from said second annular spaces is introduced to respective ones of said rolling bearings;   a thrust receiving member restraining pin extending inward of said bearing housing;   a thrust receiving member having an aperture therein to receive said thrust receiving member restraining pin to be made non-rotatable thereby while transmitting a thrust to said bearing housing;   a spring disposed between said pair of outer sleeves to bias them outwardly of said thrust receiving member; and   an oil bypass passage between an inboard end of each of said outer sleeves and an adjacent end of said thrust-receiving member, through which lubricating oil from said second pair of annular spaces is introduced to an oil outlet opening through which the lubricating oil is discharged out of said bearing housing.   
     
     
       2. A rolling bearing arrangement as claimed in claim 1, wherein: each said outer sleeve is coaxially formed at its outer periphery with first and second annular grooves which are separate from each other, said first and second annular grooves defining respectively said first and second annular spaces.   
     
     
       3. A rolling bearing arrangement as claimed in claim 2, wherein: said oil supply passage is formed through one of said outer sleeves to communicate corresponding second annular groove with an inside portion of the corresponding outer sleeve.   
     
     
       4. A rolling bearing arrangement as claimed in claim 1, wherein: each said oil film damper clearance includes said first and second oil film damper clearances, said first oil film damper clearance being formed between said first and second annular spaces in the axial direction of said outer sleeve, said second oil film damper clearance being formed on the opposite side of said first oil film damper clearance with respect to said first annular space in the axial direction of said outer sleeve.   
     
     
       5. A rolling bearing arrangement as claimed in claim 1, wherein: each said outer sleeve is coaxially formed with first and second land portions, said first land portion being located between said first and second grooves in the axial direction of said outer sleeve and defining said first oil film damper clearance, said second land portion being located on opposite side of said first land portion with respect to said first groove in the axial direction of said outer sleeve and defining said second oil film damper clearance.   
     
     
       6. A rolling bearing arrangement as claimed in claim 1, wherein: each said outer sleeve is coaxially formed at its inner periphery with an annular cutout in which an outer race of said rolling bearing is fixedly fitted.   
     
     
       7. A rolling bearing arrangement as claimed in claim 1, wherein: each said rolling bearing has an inner race to which a turbine shaft of a turbocharger is fitted.   
     
     
       8. A rolling bearing arrangement as claimed in claim 1, wherein: said oil bypass passage is defined in part by a plurality of projections provided at said inboard ends of said outer sleeves to contact said thrust receiving member.   
     
     
       9. A rolling bearing arrangement, comprising: a bearing housing;   a rolling bearing supported relative to said bearing housing;   an outer sleeve secured to and surrounding the periphery of said rolling bearing, said rolling bearing being supported through said outer sleeve to said bearing housing;   a first annular space between said outer sleeve and inner periphery of said bearing housing;   an oil inlet opening opened at the inner periphery of said bearing housing, a flow of lubrication oil being supplied through said oil inlet opening to said first annular space;   an oil film damper clearance formed between said outer sleeve and said bearing housing inner periphery and located adjacent said first annular space in an axial direction of said outer sleeve, the entire amount of a lubricating oil flow supplied to said first annular space passing through said oil film damper clearance;   a second annular space between said outer sleeve and said bearing housing inner periphery, at least a part of the lubricating oil flow passed through said oil film damper clearance being supplied to said second annular space is introduce to said rolling bearing; and   an oil bypass passage through which lubricating oil from said second annular space is introduced to an oil outlet opening through which the lubricating oil is discharged out of said bearing housing;   wherein said outer sleeve is coaxially formed at its outer periphery with first, second and third land portions, said first land portion being located between said first annular spaces in the axial direction of said outer sleeve and defining a first oil film damper clearance, said second land portion being located on an opposite side of said first land portion with respect to said first annular space in the axial direction of said outer sleeve and defining said second oil film damper clearance, said third land portion being located on the opposite side of said first land portion with respect to said second annular space and on the inner side of said second annular space in the axial direction of said outer sleeve, said third land portion defining an oil bypass between an outer periphery of said third land portion and said bearing housing inner periphery, lubricating oil in said second annular space flowing through said oil bypass passage to said oil outlet opening.